1. Field of the Invention
The present invention relates to oil solubilized solutions and foods containing phytosterols and to a process for their production, and more specifically it relates to oil solubilized solutions and foods containing phytosterols which have improving effects on benign prostatic hyperplasia and prophylactic effects against various disease such as hiper lipidemia and the like, as well as to a process for their production.
2. Description of the Prior Art
Phytosterols such as sitosterols have long been known for their inhibiting effects on cholesterol absorption, and have been used as clinical or non-prescription drugs for improvement in hyperlipidemia. However, because phytosterols tend to be poorly soluble in oil as well as water, they have been prepared either as oil suspensions or in the form of powder or granules.
Water solubilization of phytosterols is disclosed in Japanese Laid-open Patent Publication No.Sho-50-89520 and 53- 31210, but these relate to processes for producing sterol injections, not for oral administration.
It is also known that combination of phytosterols and ethylene oxide improve the solubility in water and organic solvent due to the length of the ethylene oxide chain, but this is applied for toiletries, and not for foods.
Insoluble form of phytosterols are not only poorly absorbed, but also inconvenient for common use as food additives, therefore improvements have been desired in these areas. In Germany, sitosterols have been used for symptom improvement of benign prostatic hyperplasia (see R. R. Berges, J. Windeler, H. J. Trampish, Th Senge and the .beta.-sitosterol study group. Randomized, placebo-controlled, double-blind clinical trial of .beta.-sitosterol in patients with benign prostatic hyperplasia. The Lancet, 345, 1529, 1995), but it is used in powder form because of its insoluble nature.
Refer to the following documents for uses of phytosterols as cholesterol-lowering agents.
A. Lees A. M., Mok H. Y. I., Lees R. S., McCluskey M. A. and Grundy S. M., Phytosterols as Cholesterol-Lowering Agents: Clinical Trials in Patients with Hypercholesterolemia and Studies or Sterol Balance., Atherosclerosis, 28, 325, 1997.
B. MATSUMOTO Shinzo. et al., Double-Blind Clinical Trials for ST-2, Shinyaku to Rinsho, 10, 2527 (1973).
C. SANO Tadahiro., Antiplatelet Effect of Unsaponifiable Soybean ST-2 (3rd Report), Rinsho to Riken, 59, 2611 (1982)
D. KAJIYAMA Goro. et al., Effect of DS-4046 on Hyperlipidemia, Yakuri to Chiryo, 16, 2965 (1988)
E. OTANI Reiji., Clinical Use Results for Sometol Against Hyperlipidemia, Yakuri to Chiryo, 12, 4155 (1984)
F. TAKEI Yoshio., Clinical Use Results for Sometol, Kiso to Rinsho, 19, 1684 (1985)
G. HATA Yoshichika. et al., Effects of Unsaponifiable Soybean (Soysterol) on Hyperlipidemia, Geriat. Med., 24, 1635 (1986)
It is an object of the present invention to provide oil solubilized solutions and foods containing phytosterols such as sitosterol, and particularly to provide oil solubilized solutions and foods containing plant sterols such as sitosterol with improved stability, for better absorption of the phytosterols into the body through their oil solubilization, as well as a process for their production.